Burner

ABSTRACT

The disclosure is directed toward a burner having a burner assembly and a large transparent door for viewing various components of the burner assembly and/or an integral pilot system. The burner can also include a windbox to manipulate air used by the burner assembly and/or an air manipulation device to ensure a proper air flow distribution in the burner assembly. The burner can also include a fan and a housing having holes disposed therein to permit fuel to enter various portions of the burner assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a conversion of U.S. Provisional Application having U.S. Ser. No. 61/911,827, filed Dec. 4, 2013, which claims the benefit under 35 U.S.C. 119(e). The disclosure of which is hereby expressly incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

SUMMARY OF THE INVENTION

The present disclosure is directed toward a burner that includes a burner assembly for combusting a fuel to provide heat to a heat exchanger and a large transparent door disposed in the burner for viewing components of the burner assembly and providing access to components of the burner assembly.

The present disclosure is also directed toward a burner having a a burner assembly for combusting a fuel to provide heat to a heat exchanger and an integral pilot system to light and maintain a pilot flame. The integral pilot system centrally disposed within the burner assembly. The integral pilot system includes a fuel supply, an igniter and a diffuser to distribute a stabilizing diffusion flame into a throat section of the burner assembly.

The disclosure is also directed toward a burner that includes a windbox disposed between a fan and a fuel injection section of a burner assembly to manipulate the flow of air exiting the fan. The windbox further including an air distribution device disposed therein to create a uniform air profile to flow into the fuel injection section. The burner also includes an air manipulation device centrally disposed in the burner assembly and downstream from the windbox to ensure a proper air flow distribution of fuel and air exiting the fuel injection section.

Another portion of this disclosure is directed toward a burner having a fan for forcing air into a fuel injection section disposed in a burner assembly. The burner also includes a housing disposed between a fan and a throat section, the housing having a plurality of holes disposed therein to permit the passage of fuel into the fuel injection section of the burner assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a burner constructed in accordance with the present disclosure.

FIG. 2 is a side-elevation view of the burner constructed in accordance with the present disclosure.

FIG. 3 is a front-elevation view of the burner constructed in accordance with the present disclosure.

FIG. 4 is a perspective view of the burner constructed in accordance with the present disclosure.

FIG. 5 is a top plan view of the burner constructed in accordance with the present disclosure.

FIG. 6 is a cross-sectional view of a burner assembly constructed in accordance with the present disclosure.

FIG. 7 is a perspective view of a flue gas recirculation system and an air delivery system constructed in accordance with the present disclosure.

FIG. 8A is a perspective view of an air manipulation device constructed in accordance with the present disclosure.

FIG. 8B is a flat pattern engineering view of the air manipulation device of FIG. 8A constructed in accordance with the present disclosure.

FIG. 9A is a perspective view of an air distribution device constructed in accordance with the present disclosure.

FIG. 9B is a flat pattern engineering view of the air distribution device of FIG. 9A constructed in accordance with the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure is directed to a burner 10 for use with a heat exchanger, such as a boiler 12 (boiler/burner components shown in FIGS. 1-3). The present disclosure is also directed toward a method of applying heat to a heat exchanger using the burner 10 described herein. In one embodiment, shown in FIGS. 4-5, the burner 10 includes a burner assembly 14 for directing and supplying a heat source, and a fan 16 for supplying air to and through the burner assembly 14. The burner 10 can also include a flue gas return system 18 for directing at least a portion of the flue gas back to the fan 16. In another embodiment, the portion of the flue gas can be directed to an air duct 20, which can process/filter air and mix the air and the flue gas prior to this mixture entering the fan 16 and the burner assembly 14.

The burner assembly 14, shown in FIG. 6, includes a windbox 22 and an air distribution device 56 for manipulating the flow of air that flows through the burner assembly 14, a gas injection section 24 for manipulating the flow of gas into the burner assembly 14 to be mixed with the air coming from the windbox 22, a throat section 26 where primary combustion of the air and gas mixture occurs, and an integral pilot system 28 centrally disposed within the burner assembly 14. The integral pilot system 28 maintains a pilot flame, ignites a main premix flame and is a stabilizing diffusion flame to anchor the main premix flame in the throat section 26. It should be understood and appreciated that the term “gas” used herein can be any type of gaseous material capable of being used to fuel a burner.

The integral pilot system 28 includes a gas supply 30, an igniter 32, an air manipulation device 44 (FIGS. 8A and 8B) and a diffuser 34 for anchoring the main premix flame in the throat section 26. The igniter 32 extends into the diffuser 34 to ignite the gas flowing from the gas supply 30 into the diffuser 34. The diffuser 34 is designed such that the stabilizing diffusion flame is sufficiently distributed into the throat section 26 to ignite the air and gas mixture entering the throat section 26 from the windbox 22 and the gas injection section 24. The use of this pilot system 28 allows for higher burner turndown ratios. The capacity of the pilot system 28 can be easily increased by increasing the size of the pilot gas train size. The capacity of the pilot system 28 can be in a range up to about 20 percent of the capacity of the burner 10.

The air manipulation device 44 is a cylindrically-shaped tube and has a first end 45 and a second end 47. The first end 45 can be attached to a backside portion of the diffuser 34. The air manipulation device 44 is designed to ensure a proper air flow distribution in the throat section 26 by allowing a gradual transfer of air to this section over the length of openings 46 disposed in the second end 47 of the air manipulation device 44. The openings 46 cooperate to create a plurality of baffles 48. In one embodiment, the openings 46 are triangular shaped. In one embodiment, the length of the triangular shaped openings 46 is in a range of from about 6 inches to about 12 inches. In another embodiment, the length of the triangular shaped openings 46 is in a range of from about 20 percent of the length of the air manipulation device 44 to about 50 percent of the length of the air manipulation device 44.

In another embodiment, shown in FIG. 7, the flue gas return system 18 includes an inlet 36 in gaseous communication with the boiler 12 for receiving flue gas from the boiler 12, an outlet 38 in gaseous communication with the air duct 20, a duct 40 disposed between the inlet 36 and the outlet 38, and a damper 42 for controlling the flow of flue gas into the air duct 20.

The windbox 22 includes an air distribution device 56 (FIGS. 9A and 9B) disposed therein for creating a uniform air profile for flowing through the gas injection section 24. The air distribution device 56 is a cylindrically-shaped tube and includes a plurality of openings 58 that cooperate to create a plurality of baffles 60 that the air from the fan 16 flows through and around prior to entering the gas injection section 24. In this embodiment, the air is forced in a direction that is perpendicular to the length of the air manipulation device 56. Thus, the air manipulation device 56 is disposed in the windbox 22 such that the air from the fan 16 flows across it perpendicularly. In yet another embodiment, the air distribution device 56 can include a second set of baffles 62 attached to and extending outward from the baffles 60. Each of the baffles 62 can have a length and width that varies in a range of from about 30 percent of the length of the windbox 22 in the axis of the air manipulation device 56 to about 100 percent of the length of the windbox 22 in the axis of the air manipulation device 56.

In a further embodiment of the present disclosure, the openings 58 are triangular shaped wherein one of the corners of the triangular shaped openings 58 is a rounded corner 59. In a further embodiment of the present disclosure, the radius of curvature of the rounded corner 59 is greater than about 1 inch.

The gas injection section 24 includes a housing 50 having a plurality of holes 52 disposed therein for the injection of gas into the burner assembly 14. The holes 52 can be varied in size (diameter), shape, location, and number to create a better mixture of the gas and air that is premixed prior to entering the throat section 26. For example, some of the holes 52 can have a larger diameter to allow for a deeper injection of gas into the air cross flow in the gas injection section 24.

Moreover, some of the holes 52 can have a smaller diameter to force a shallow injection of gas into the air cross flow in the gas injection section 24. Changing the size, shape, location and number of holes 52 disposed in the housing 50 permits more control of the amount of premix of the gas and air prior to encountering the premix flame. The mixing of the gas and air is done upstream of the mixture contacting the main premix flame and combusting in the throat section 26.

In one embodiment, the larger holes 52 can have a diameter in a range of from about 3/16 inch to about ½ inch. The smaller holes 52 can have a diameter in a range of from about 1/16 inch to about ¼ inch. In yet another embodiment, the housing 50 can include medium sized holes 52 to facilitate the injection of fuel/gas into the gas injection section 24 a distance greater than the smaller holes 52 and less than the larger holes 52. The medium sized holes 52 can have a diameter in a range of from about ⅛ inch to about ⅜ inch.

In another embodiment, the smaller holes 52 have diameters that are in a range of 30 percent to about 50 percent of the diameters of the larger holes 52. Similarly, the medium sized holes 52 have diameters that are in a range of 60 percent to about 75 percent of the diameters of the larger holes 52. Similarly, the smaller holes 52 have diameters that are in a range of 50 percent to about 70 percent of the diameters of the medium sized holes 52.

The centrally-disposed pilot system 28, and the more homogenous premix, permits the burner 10 to have ultra-low NOx emissions (less than 10 ppm) while maintaining a stable combustion of the air and gas mixture starting in the throat section 26.

In a further embodiment of the present disclosure, the burner 10 includes a large door 54 hingedly attached to a portion of the burner 10. The door 54 can be constructed of a transparent material, such as double pane glass, to allow visual inspection of various internal parts of the burner assembly 14 and the fan 16. In one embodiment, the transparent material makes up at least 50 percent of the area of the door 54. In another embodiment, the transparent material makes up at least 80 percent of the area of the door 54.

In one embodiment, the door 54 is sized such that access to the burner assembly 14 is permitted to an individual and/or allows various components of the burner assembly 14 to be removed via the door 54. In one embodiment, the door 54 has a diameter in a range greater than about 16 inches. In another embodiment, the door 54 has a diameter in a range of greater than about 28 inches.

In one embodiment, the door 54 can be located on the windbox 22. This permits access to burner components almost immediately after the burner is shut off because the design of the burner 10 is such that a number of burner components are cooled quickly by the fan 16. The door 54 made of see-through glass eases the diagnostic process of the burner 10 when problems arise.

The present disclosure is also directed to a method of using the burner 10 described herein. The method includes the step of forcing air into and through the burner assembly 14 via any manner known in the art, such as the fan 16 described herein. The method can also include mixing the air forced into the burner assembly 14 with a fuel, or gas, to create a combustion mixture. The combustion mixture can then be combusted to create heat to be provided to the boiler 12 (or heat exchanger). In a further embodiment, the method includes the step of mixing the air forced into the burner assembly 14 with a portion of flue gas removed from the boiler 12 via the flue gas return system 18.

From the above description, it is clear that the present disclosure is well adapted to carry out the objectives and to attain the advantages mentioned herein as well as those inherent in the disclosure. While embodiments have been described for purposes of this disclosure, it will be understood that numerous changes may be made which will readily suggest themselves to those skilled in the art and which are accomplished within the spirit of the disclosure. 

What is claimed is:
 1. A burner, the burner comprising: a burner assembly for combusting a fuel to provide heat to a heat exchanger; and a large transparent door disposed in the burner for viewing components of the burner assembly and providing access to components of the burner assembly.
 2. The burner of claim 1 further comprising a flue gas return system for directing a portion of flue gas present in the heat exchanger back to the burner assembly, the flue gas system comprising: an inlet to the flue gas return system in gaseous communication with the heat exchanger; an outlet from the flue gas return system in gaseous communication with the burner assembly; and a duct disposed between the inlet and outlet.
 3. The burner of claim 2 wherein the flue gas return system further comprises a damper that can be selectively opened and closed to control the amount and flow rate of flue gas entering the burner assembly.
 4. The burner of claim 1 wherein the large door has a diameter greater than about 16 inches.
 5. The burner of claim 1 wherein the large door has a diameter greater than about 28 inches.
 6. The burner of claim 1 wherein at least 50 percent of the large door is constructed of a transparent material.
 7. The burner of claim 1 further including a fan for forcing air into the burner assembly, the burner assembly further comprising: a windbox to manipulate the flow of air exiting the fan; a fuel injection section for providing fuel into the burner assembly to mix with the manipulated air exiting the windbox; an integral pilot system to light and maintain a pilot flame; and a throat section where primary combustion of the mixture of the air and fuel is initiated.
 8. The burner of claim 8 wherein the integral pilot system is centrally disposed within the burner assembly and includes a fuel supply, an igniter and a diffuser to distribute a stabilizing diffusion flame into the throat section of the burner assembly.
 9. The burner of claim 9 wherein the fuel injection section provides the fuel into the burner assembly to mix with the manipulated air prior to the fuel and air encountering the stabilizing diffusion flame extending from the diffuser of the integral pilot system.
 10. The burner of claim 8 wherein the windbox includes an air distribution device disposed therein to create a uniform air profile to flow into the fuel injection section.
 11. The burner of claim 11 wherein the air distribution device is a substantially cylindrically shaped tube having a plurality of openings disposed therein that create baffles that extend along a length of the cylindrically shaped tube.
 12. The burner of claim 12 wherein the openings and the baffles are substantially triangular shaped and one corner of the opening is rounded and has a radius of curvature greater than about 1 inch.
 13. The burner of claim 12 wherein the air from the fan flows into the windbox and perpendicular to the length of the air distribution device.
 14. The burner of claim 8 wherein the burner assembly further includes an air manipulation device centrally disposed in the burner assembly and downstream from the windbox to ensure a proper air flow distribution of the fuel and air entering the throat section.
 15. The burner of claim 15 wherein the air manipulation device is a substantially cylindrically shaped tube having a plurality of openings disposed therein that create baffles that extend along a predetermined length of the cylindrically shaped tube.
 16. The burner of claim 16 wherein the openings and the baffles of the air manipulation device are substantially triangular shaped and one corner of the opening is rounded and has a radius of curvature greater than about 0.1 inch.
 17. The burner of claim 16 wherein the air manipulation device has a first end connected to a backside of the diffuser and a second end having the openings disposed therein.
 18. The burner of claim 8 wherein the fuel injection section further includes a housing disposed between the windbox and the throat section, the housing has a plurality of holes disposed therein to permit the passage of fuel into the burner assembly.
 19. The burner of claim 19 wherein the holes disposed in the housing vary in size to facilitate the depth at which the fuel is injected into the fuel injection section to adequately mix the manipulated air exiting the windbox and the fuel passing through the holes.
 20. A burner, the burner comprising: a burner assembly for combusting a fuel to provide heat to a heat exchanger; an integral pilot system to light and maintain a pilot flame is centrally disposed within the burner assembly, the integral pilot system includes a fuel supply, an igniter and a diffuser to distribute a stabilizing diffusion flame into a throat section of the burner assembly.
 21. The burner of claim 21 wherein the fuel injection section provides the fuel into the burner assembly to mix with the manipulated air prior to the fuel and air encountering the stabilizing diffusion flame extending from the diffuser of the integral pilot system.
 22. The burner of claim 21 wherein the burner assembly further includes an air manipulation device centrally disposed in the burner assembly and downstream from the windbox to ensure a proper air flow distribution of the fuel and air entering the throat section.
 23. The burner of claim 23 wherein the air manipulation device is a substantially cylindrically shaped tube having a plurality of openings disposed therein that create baffles that extend along a predetermined length of the cylindrically shaped tube.
 24. The burner of claim 24 wherein the openings and the baffles of the air manipulation device are substantially triangular shaped and one corner of the opening is rounded and has a radius of curvature greater than about 0.1 inch.
 25. The burner of claim 24 wherein the air manipulation device has a first end connected to a backside of the diffuser and a second end having the openings disposed therein.
 26. A burner, the burner comprising: a windbox disposed between a fan and a fuel injection section of a burner assembly to manipulate the flow of air exiting the fan, the windbox having an air distribution device disposed therein to create a uniform air profile to flow into the fuel injection section; and an air manipulation device centrally disposed in the burner assembly and downstream from the windbox to ensure a proper air flow distribution of fuel and air exiting the fuel injection section.
 27. The burner of claim 27 wherein the air distribution device is a substantially cylindrically shaped tube having a plurality of openings disposed therein that create baffles that extend along a length of the cylindrically shaped tube.
 28. The burner of claim 28 wherein the openings and the baffles are substantially triangular shaped and one corner of the opening is rounded and has a radius of curvature greater than about 1 inch.
 29. The burner of claim 28 wherein the air from the fan flows into the windbox and perpendicular to the length of the air distribution device.
 30. The burner of claim 27 wherein the air manipulation device is a substantially cylindrically shaped tube having a plurality of openings disposed therein that create baffles that extend along a predetermined length of the cylindrically shaped tube.
 31. The burner of claim 31 wherein the openings and the baffles of the air manipulation device are substantially triangular shaped and one corner of the opening is rounded and has a radius of curvature greater than about 0.1 inch.
 32. The burner of claim 31 wherein the air manipulation device has a first end connected to a backside of the diffuser and a second end having the openings disposed therein.
 33. A burner, the burner comprising: a fan for forcing air into a fuel injection section disposed in a burner assembly; a housing disposed between a fan and a throat section, the housing having a plurality of holes disposed therein to permit the passage of fuel into the fuel injection section of the burner assembly.
 34. The burner of claim 34 wherein the holes disposed in the housing vary in size to facilitate the depth at which the fuel is injected into the fuel injection section to more thoroughly mix the manipulated air exiting the windbox and the fuel passing through the holes. 